code: def convert_matlab_date(
      df: pd.DataFrame, column_name: Hashable
  ) -> pd.DataFrame:
      """Convert Matlab's serial date number into Python datetime format.
  
      Implementation is also from
      [Stack Overflow](https://stackoverflow.com/questions/13965740/converting-matlabs-datenum-format-to-python).
  
      This method mutates the original DataFrame.
  
      Examples:
          >>> import pandas as pd
          >>> import janitor
          >>> df = pd.DataFrame({"date": [737125.0, 737124.815863, 737124.4985, 737124]})
          >>> df
                      date
          0  737125.000000
          1  737124.815863
          2  737124.498500
          3  737124.000000
          >>> df.convert_matlab_date('date')
                                  date
          0 2018-03-06 00:00:00.000000
          1 2018-03-05 19:34:50.563200
          2 2018-03-05 11:57:50.399999
          3 2018-03-05 00:00:00.000000
  
      Args:
          df: A pandas DataFrame.
          column_name: A column name.
  
      Returns:
          A pandas DataFrame with corrected dates.
      """  # noqa: E501
      days = pd.Series([dt.timedelta(v % 1) for v in df[column_name]])
      df[column_name] = (
          df[column_name].astype(int).apply(dt.datetime.fromordinal)
          + days
          - dt.timedelta(days=366)
      )
      return df
  
file_path: pyjanitor/janitor/functions/convert_date.py
imports: import datetime
  from typing import Hashable
  import pandas
  import pandas_flavor
  from pandas.api.types import is_numeric_dtype
  from pandas.errors import OutOfBoundsDatetime
  from janitor.utils import deprecated_alias
label_desc: Use image node_id 2 for calling a global function with example usage: convert_matlab_date(df, column_name) and returns: df